Map和模糊查询拓展

深碍√TFBOYSˉ_ 2023-02-19 15:27 2阅读 0赞

Map传递参数，直接在sql中取Key即可

parameterType="map"

对象传递参数，直接在sql中取对象的属性即可

parameterType="Object(具体的对象)"

只有一个基本类型的情况下，直接在sql中取到

多个参数用Map或**注解**

### 用例 ###

编写mapper

public interface UserMapper {
        
        public void updateUser2(Map<String,String> map);
    }

<?xml version="1.0" encoding="UTF-8" ?>
    <!DOCTYPE mapper
            PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
            "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
    
    
    <mapper namespace="com.study.dao.UserMapper">
    
        <update id="updateUser2" parameterType="map">
            update user set name=#{
        username} where id=#{
        userId}
        </update>
    
    </mapper>

编写Junit测试

package com.study.dao;
    
    import com.study.pojo.User;
    import com.study.utils.MybatisUtils;
    import org.apache.ibatis.session.SqlSession;
    import org.junit.Test;
    
    import java.util.HashMap;
    import java.util.List;
    import java.util.Map;
    
    public class UserDaoTest {
        
    
        @Test
        public void updateTest2(){
        
            //1、获取sqlSession
            SqlSession sqlSession = MybatisUtils.getSqlSession();
            UserMapper mapper = sqlSession.getMapper(UserMapper.class);
    
            Map<String,String> map = new HashMap<String, String>();
            map.put("userId","1");
            map.put("username","小狗");
            mapper.updateUser2(map);
    
            //2、提交事务
            sqlSession.commit();
    
            //3、关闭sqlSession，防止内存泄漏
            sqlSession.close();
        }
    }

结果展示：

mysql> select * from user;
    +----+--------+-------+
    | id | name   | pwd   |
    +----+--------+-------+
    |  1 | 小明   | 12345 |
    |  2 | 张三   | 12345 |
    |  3 | 李四   | 12345 |
    +----+--------+-------+
    3 rows in set (0.00 sec)
    
    mysql> select * from user;
    +----+--------+-------+
    | id | name   | pwd   |
    +----+--------+-------+
    |  1 | 小狗   | 12345 |			# 修改之后
    |  2 | 张三   | 12345 |
    |  3 | 李四   | 12345 |
    +----+--------+-------+
    3 rows in set (0.00 sec)